there you see him right there, dzhokhar tsarnaev, 19 years old. a graduate of boston latin high school been in the united states for 12 years believed to be of chechen origin. thousands have converged on watertown where there is a massive shootout last night that killed suspect number one, his brother. during the night they were using weapons, they were using explosives, they were using bombs and right now we're about g delayer at the neorat any moment because at this time, police have surrounded an area where they believe suspect number two may be holed up at this time and, of course, we wouldn't want to do anything that would compromise the tactical situation facing the boston police right now, they have asked us not to do that. we will not share any information that could compromise what is going on right now but i do want to go to abc's pierre thomas in washington with the latest on the suspects and what the fbi is finding. pierre. >> reporter: george, this situation is so tense in part because they believe that the suspect has an assault rifl